Electrical connectors of the plug and receptacle type are used in many applications for connecting one pair or multiple pairs of corresponding wires. The wires at the receptacle are connected to individual terminals and the wires at the plug are connected to corresponding terminals. Each of the terminals comprises an electrical contact having a wire receiving end and a mating end. The mating end of corresponding contacts are matingly engaged to provide electrical continuity therebetween when the plug and receptacle are connected together. It is known in the prior art to use electrical contacts of the hermaphroditic type, i.e. the mating ends of the corresponding contacts are of identical structure. Hermaphroditic contacts are advantageous in that identical contacts are used on both the plug and receptacle and hence there is economy in manufacture and field service. However, in the prior art, there have been difficulties in making hermaphroditic contacts at low cost which provide good electrical connection together with low insertion force which is especially important in multiple contact connectors.
An important application for hermaphroditic contacts is that of miniaturized connectors such as those used in aerospace electronic systems. In such connectors, the contacts need to be very small; for example a contact may be about one tenth inch diameter and about one-half inch long. Typically, miniature contacts have been of the pin and socket type. When miniature pin and socket contacts were first introduced, they were manufactured by machining from metal stock in order to hold the tolerances required for the mating contacts. In recent years, such contacts have been made from sheet metal by stamping and rolling to produce the so-called "formed" contact. Formed contacts comprise a tubular assembly having a wire receiving end and a mating end and a mounting or locking shoulder therebetween. The mating end of the socket contact is provided with plural cantilevers or contact fingers adapted to receive the pin contact. A contact of this construction and the method of making it are described in U.S. Pat. No. 4,072,394 to Waldron, et al. and assigned to the same assignee as this application.
In the prior art, hermaphroditic contacts are known in which each contact comprises a single blade having a slot defined by shaped edges and extending rearwardly from the free or mating end of the blade. A pair of such contacts are placed in mating engagement by orienting the respective blades in perpendicular planes with the slots aligned and inserting one blade over the other in telescoping relationship. One difficulty with this device is that the blades are unyielding in the plane of the blades and good electrical contact cannot be obtained without high insertion force.
In the prior art connectors, it is known to use contacts which are insertable and removable in the body of the connector to facilitate initial hook-up and servicing of a connector. Typically, the contact is provided with an annular mounting or locking shoulder intermediate the wire receiving and the mating ends which coacts with a retention member in the connector. The retention member has plural resilient fingers which flex to allow insertion of the contact and which seat behind the locking shoulder to hold the contact in place. The contact is removable with the aid of a special tool for deflecting the fingers from the locking shoulder. A contact of this type is disclosed in U.S. Pat. No. 4,082,398 to Bourdon et al.
A general object of this invention is to provide an improved electrical contact of hermaphroditic type and also to provide an improved locking arrangement for an insertable and removable contact.